Arc striking and extinguishing apparatus



E. A. SPERRY.

ARC STRIKING AND EXTINGUISHING APPARATUS.

- API LICATION FILED JULY 22,1916.

[WEN-TOR EL MER H. SPERRY FIG-l.

UNITED STATES PATENT OFFICE.

ELMER A. SPERRY, OF BROOKLYN, YORK.

ARC STRIKING AND EXTINGUISHING APPARATUS.

Specification of Letters Patent.

- Patented May 31, 1921.

Application filed July 22, 1916. Serial No. 110,753.

To all whom it may concern: v Be it known that I, ELMER A. SPERRY,

a citizen of the United States, residing at ordinary are light as in a.searchlight the.

electrodes are normally placed in an approximately horizontal positioninstead of vertical, and are quite a distance from the controllingmechanism which is necessarily placed without the drum.

The main object of the invention is to devise a simple are strikingmeans which is 0 erable, without disturbing the position of eitherelectrode holder or electrode, so that the structure of the electrodeholders and feeding mechanism therefore may be made very simple. Anotherobjectof the invention is to devise in connection with my novel arestriking means a light extinguishing means, whereby the light from thesearchlight may be shut off instantaneously, by shutting ofl:' the usualafterglow. My invention possesses especial advantages when used inconnection with searchlights of the type shown in my copendingapplication for improvements in searchlights, Serial No. 21661, filedApril 16, 1915, in which for ordinary feeding, the electrode holdersremain stationary, and the electrodes are fed through the holders. Inthis form, also, the holders are artificially cooled by air introducedthrough the supports for the electrodes.

Referringto the drawings, in which what I now consider to be thepreferred form of my invention is shown,

Figure 1 is a vertical longitudinal section of a portion of aSearchlight, showing portions of the two electrode holders.

,Fig. 2 is a section on line 2-2, Fig. 1, the positive holder, however,being omitted.

Fig. 3 is a detail of the automatic mechanism for operating the arestriking flipper.

Fig. 4 is a view of a small portion of Fig. 1, showing in full, partswhich are there shown in section.

In the specific embodiment shown, both the positive holder 1 and thenegative holder 2, are located within drum 10 adjacent to the arc, andthe electrodes 3 and 4 are normally fed therethrough by automaticmechanism hereinafter described, actuatedv in part by electric motor 5in the control box 6. The said control box is shown suspended withoutthedrum 10*, by means of a strip 80 on said box, running between guidestrips 81 and 82 on said drum. The support 7 for holder 1, which may betaken as typical of both supports, is made hollow to serve as a duct forleading in air to the holder from the fan blower 8 operated by motor 5.To cut ofl stray light from the negative and from the arc flame, I-prefer to provide the positive holder with a shield 9.

Mounted near the arc is a movable member 10 which I term the arestriking flipper. I prefer to pivotally mount the flipper to one side ofthe arc and actuate it automatically. As shown, the flipper is pivotedupon a shaft 11 secured to and extending from the support 7 of theholder 1. The flipper 10 may be formed of any refractory material whichwill conduct electricity, such as carbon or the like. It is shown as adisk 75 clamped between flanges 76, 77 on an enlarged head 78 on stem30.

"in brackets 15 and 16 secured to standard 7. A bevel gear 18 is securednear the top of the shaft 14 and meshes with a pair of bevel gears 19and 20, journaled on shaft 11. sleeve 21, loosely mounted on shaft 11. Ahub 22 which supportsthe stem 23 of shield 13 is secured near the outerend of sleeve 21. o Bevel gear 19 is loosely mounted on sleeve 21 andhas secured thereto the hub 2 1 of the stem 25 supporting shield 12. Bythis construction it will be seen that the two shields are rotated inopposite .directions about shaft 11 by the rotation of shaft 14; Anysuitable means may be provided for holding the member 10 normallyagainst against the electrodes. For this purpose a counter Weight 26' isshown. Counter Bevel gear 20 is secured to a long weights 27 and 28 mayalso be provided for the shields 12 and 13, respectively, if

desired. The hub 29 supporting stem 30 of the flipper 10 is providedwith a plurality of lugs, 31, 71 and 72. Lug 31 lies. 1n the path of thestem 23' and is adapted to-be struck thereby after a predetermlned r0-tation of stem 23away from the upstandlng position, has taken place (seethe dotted position 13, Fig. 2). The lug 72 is in the nature of a limitstop for all of the rotatable members, and is arranged to strike the pin43 secured to shaft 11 in the open position of the parts. Lug 71 isarranged to be struck by the stem 23 very shortly before shield13.reache 's the closed position, so that the flipper 10 will be broughtinto intimate contact with the two electrodesas the two shields closetogether. It is obvious that counter weight 26 will cause the flipper 10to engage the electrodes before stem 23 engages lug 71. It will bereadily seen then .that 'stem 30 which is shown as very slender, isdesigned'to bend to allow shield 13 to reach its closed position. Thisslender wire construction for stem is also designed to facilitate theengagement of the flipper with both electrodes. In the open position ofthe parts (12", 13", 10") the shields and flipper are designed to lie inthe blind spot of the projector, that is, in the shadow cast by thenegative electrode holder 2. Y

The arrangement is such that when it is desired to start the arc, shaft14 is rotated, which will first move the shields away from the arc'toabout the position shown at 13, 12' in Fig. 2. At this point the stem 23will strike lug 31 and rotate the flipper 10 away from its contact withthe .two electrodes. This will immediately draw or cause an arc to formbetween the two electrodes. Continued rotation of the shaft will removethe shields and flipper to the approximate position shown in 'Fig. 2 at10 and'13 and 12.

The shaft 14 may be rotated either by hand or automatically from the arelight circuit. A handle 35 is shown tooperate the shaft by hand, while asolenoid 36, preferably in series withthe arc, is shown for operating itautomatically. For this purpose the core 37 of the solenoid is connectedto a bell' crank lever 38 which in turn isconnected to a sliding link39. Said link is pivotally connected to an arm 40 secured to shaft l l,so that when the solenoid is energized, said shaft will be rotated. Whenthe current is shut off the shields are quickly and automatically closedabout the tips of the electrodes and the flipper'returned to itsposition in contact with electrodes by a spring 41 shown as securedbetween the fixed pin 42 and bell crank lever 38. A dashpot 43' alsosecured to said lever may stopping motor 5. the current to motor 5 wouldbe shut off be provided to prevent the too sudden opening and closing ofthe shields and flipper. Connected with this mechanism so as to beoperated thereby is a means for positively stopping the feeding of theelectrodes when the flipper engages said electrode, so that jamming ofthe electrodes will be guarded against. In my preferred type of lamp oneor both of the electrodes, 3, is rotated and fed within and through theholder 1 by mechanism located within the holder and actuated from themotor 5 in the control box through shaft 51. This mechanism is shown ascomprising a large bevel gear 52 meshing with gear 61 on shaft 51 androtatably mounted in holder 1. Gear 52 is provided with an extended hub53 which supports the feed rollers 54 and 55, so that the rollers notonly feed but also rotate the carbon.- The rollers are geared togetherby gears 56 and 57 and aredriven through an idler 58 from a toothed orstar wheel 59 which strikes a detent 60 once every rota-' tion of gear52. Detent 60 is movable to: ward and away from the path of the wheel59, its position being automatically controlled to effect feeding at thedesired rate. Between motor 5 and the bevel gears 62, 63 by means ofwhich it drives shaft 51, is located a friction clutch 64, which willallow shaft 51 to stop without stopping the motor.

to move axially thereon, pressed by spring.

S against disk 64 rigidly secured. tosection 5 of said shaft 5?. Onshaft 51 is mounted a star wheel 65 or similar device ,(see Fig. 3), andon rod 39 or other part of the mechanism operating flipper 10, is a pin66 adapted to be struck by said wheel when flip-per 10 is closed. Bythis or similar means, both the rotation and feeding of either, or bothof the electrodes are positively prevented without the necessity ofWhile, in most cases,

when the arc is extinguished, it is "sometimes found advantageous tokeep it running to exhaust the fumes in the drum thoroughly.

Furthermore it is found that, due to the high speed of motor 5, it willnot stop for some tlme afterthe current is shut Ofl", so that withoutmeans to prevent feeding during this time, the flipper and electrodesmight be damaged.

In accordance with the provisions of the 7 patent statutes, I haveherein described the principle of operation of my invention, to-

gether with the apparatus, which I now consider to represent the bestembodiment thereof, but I desire to have it understood that theapparatus shown is only illustrative and that the invention can becarried out by other means. Also, while it IS designed to ,claim anddesire to secure by Letters Patent is 1. The combination with are lightelectrodes, of a light shield and a movable are striking member thereforand means responsive to changes in the energizing current for operatingthe shield and member.

2-. In an are light, the combination with the electrodes and electrodeholders and an arc striking mechanism therefor, of a light shield forextinguishing the after glow com-- prising a pair of pivoted membersadapted to normally inclose the electrode tips, means for removing saidmembers from said tips and means brought into action by said removal foroperatlng said are striking mechanism. 4

3. The combination with a pair of electrodes,

a movable are striking member, means for removing the shield on startingthe are, and

a connection between said shleld and said member whereby the member iswithdrawn to strike the are by the shield.

4. The combination with a pair of electrodes, of a removable lightshield therefor, a movable are striking member, means for removing theshield on starting the arc, and a lost motion connection between saidshield and said member whereby the member is withdrawn to strike the areafter the withdrawal of the shield.

, 5. The combination with a pair of electrodes, of a removable lightshield therefor, a movable arc striking member, means for closing theshield on shuttin off the arc current, and a connection etween saidshield and said member whereby the closing of the shield forces themember into contact with the electrodes.

6. In a searchlight, having a pair of spaced electrodes, a movablemember adapt ed to engage the are tips of both of said electrodes,shields for inclosing said tips, means for normally closing saidshields; means for causing said shields to press said member intocontact with both of said electrodes, and means controlled by theturning on of the arc current for opening said shields and forwithdrawing said member from said electrodes.

7 In an are light, the combination with spaced electrodes, 0 a lightshield adapted to inclose the are tips of said electrodes, means formoving said shield to its operative position, an are striking memberpivoted near said electrodes, means for causin said member to engage atleast one of sai of a removable light shield therefor,

.ing

tips, means for causing said shield to exert pressure on said memberafter said member has engaged one of said tips and before said shieldhas reached its operative position for causing said member to yield andmove into contact with the other of said tips.

8.. In an are light, the combination with spaced electrodes, of a rodpivoted near said electrodes, a member on said rod for engaging the arctips of said electrodes, an arc inclosing shield, means for moving said.shield into operative position, a lug connected with said rod adaptedto be actuated bysaid shield to move said member into contact with saidtips, said lug being so positioned as to cause said member to touch atleast one of said tips before said shield reaches its operativeposition.

9. In a Searchlight, the combination with a drum, adapted to containelectrodes there-' in, of feeding mechanism for said electrodes, amovable member adapted to bridge the space between said electrodes,electrically operated means without said'drum for actuating saidmechanism and said member and means controlled by the position of saidmember for locking said feeding mechanism against operation.

.10. In an are light, the combination with spaced electrode holderspositioned in line and facing one another, each holder being adapted tosupport feeding mechanism for an electrode,a member located between saidholders and adapted to touch both electrodes in one position, means formoving said member away from and toward said electrodes and meansresponsive to said last named movement for sto ping said mechanism.

11. In a search ight employing a pair of electrodes, means for inclosingthe arc-tips of said electrodes, a movable member adjacent said are tipsadapted to touch the same, means for moving said inclosing means, andsaid member into operative position, means for retarding the speed ofsaid moving means and electromagnetic means in circuit with saidelectrodes for withdrawing said member to strike the arc and forremoving said inclosing means to an inoperative position when the arc isstruck.

12. In a Searchlight employing a pair of spaced electrodes, are tipinclosing means comprising a plurality of light shields pivoted adjacentsaid electrodes, counterweights for, moving said shields into closedposition, an arc striking means also pivoted tact with said electrodes,additional means for pressing said shields and said are strikmeans intooperative position, and means brought into action by the turning on ofthe arc current for moving said shields and said are striking means toinoperative positions.

13. In a Searchlight the combination with fixed electrode holdersadapted to cause the electrodes to be fed therethrough, of a movablemember adapted to bridge the space be tween said electrodes, and meansfor withdrawing said member into a position in Which it lies in theshadow cast by one of the holders. v

14:. The combination with are light electrode holders, of a light shieldand a movable arc striking member therefor and means whereby both saidshield and said members may be moved to a position in line with one ofthe electrode holders to prevent the casting of a separate shadow. a

15. In an are light, the combination with spaced electrodes, holders forthe electrodes,

' and supports for said holders, of a shaft secured to one of saidsupports, a pair of sleeve members on said shaft, means for rotatingsaid members in opposite directions, a pair of arc tip inclosingshields, and means for securing each of saidshields to one of saidmembers.

16. An arc lamp for searchlights' comprising in combination, means forstriking the are without causing relative movement of the arcelectrodes, and means for moving said first named means into the shadowof a part of the lamp structure.

In testimony whereof I have afiixed my signature.

ELMER A. SPERRY.

